That application, and other disclosures such as U.S. Pat. No. 3,892,958 to C. Tung of July 1, 1975; U.S. Pat. No. 3,967,273 to K. Knowlton of June 29, 1976; and European Patent Application 11,307 filed Nov. 19, 1979 all relate to the multiple use of keyboard keys for reducing the number of keys required on a keyboard for processing data. This is particularly desirable for miniaturized multi-purpose computer systems now feasible in the art which are capable of many hundreds of functions and which may require both numerics and alphabets in their communication, calculating and data processing operations.
The Knowlton patent, for example, reduces the number of keys required for alphanumeric capabilities to twelve by requiring two successive choices for every entry digit such as numeral 2 or letter k. The Tung patent provides for each key to have at least three functions with two sets of functions respectively chosen by respective orange or blue prefix key so that a calculator with thirty-two keys can be used for about three times that many functional computer entries including instructions and data. This latter concept is used, for example, in "Hewlett-Packard" Model HP-41 type programmable calculators with full alphabetic capabilities. Similarly "Texas Instruments" TI-88 line of programmable calculators have alphabetic capabilities with two keyboard functions selectable, plus an alphabetic entry mode.
The general state of the art of calculator systems with complex many functional capacity is represented by U.S. Pat. No. 3,863,060 to F. Rode et al., of Jan. 28, 1975.
However, the state of such prior art calculators has made programming and particularly programming in the alpha mode awkward and time consuming because of the necessity to sequence varying multiples of keystroke entries for entering alphabet letters into program steps being formulated.
Also, many of these prior art calculators have introduced alpha capabilities at the expense of utilizing 26 separate keys for the alphabet. Thus, calculators or computers with few key keyboards in the art have been deficient in their capacity to control many calculator functions with concurrent alphanumeric capability that can be easily used and rapidly programmed in the alphanumeric mode.
It is therefore an objective of this invention to provide improved alphanumeric capabilities in computers and data processing systems, and in particular to overcome the aforesaid deficiencies of the prior art. Other objects, features and advantages will be found throughout the following description, drawing and claims.